1. Field of the Invention
The present invention relates to an apparatus and method for handling a card. More specifically, the present invention relates to an apparatus and method for handling a card which holds value data that is renewed for each payment or settlement for transactions.
2. Description of the Prior Arts
In such a card system, typically, a magnetic card, IC card or the like for which a predetermined amount of money has been paid in advance (simply called as "prepaid card") is used as the value medium capable of payment for items or transactions.
One example of such a kind of a prepaid card handling apparatus is disclosed in, for example, Japanese Patent Laying-Open No. 61-283995. In this prior art, when a magnetic prepaid card is inserted to a reader/writer in order to effect a payment or settlement for an item or transaction, value data recorded in the magnetic prepaid card is read. Then, a price of the item is subtracted from the value data, and value data which is thus renewed is recorded in the magnetic prepaid card again, and the magnetic prepaid card is returned to a card user.
In a prepaid card handling apparatus in which transactions are settled by utilizing such a prepaid card, it is apprehended that the value data recorded in the magnetic prepaid card is unjustly altered or that value data is unjustly written in the magnetic prepaid card.
In addition, one method for preventing such alternation of the value data is disclosed in, for example, Japanese Patent of Laying-Open No. 63-101961. In this prior art, only when a timing signal is written in a specific magnetic stripe, it is possible to read or write value data from or in the magnetic stripe, while the timing signal is erased when the value data becomes "0".
In this prior art, it is also impossible to completely prevent the value data from being altered unjustly because only a specific kind of a reader/writer can control the reading or writing the value data in accordance with the presence or absence of the timing signal and, if another kind of a reader/writer is used, the value data can be unjustly altered again.
Furthermore, if a failure or trouble develops in a magnetic head of a reader/writer for writing or reading the value data in or from a magnetic prepaid card, sales of the items or transactions may be obstacled. For example, if a payment is effected even although a writing head goes wrong, the renewed value data after the payment cannot be written in the magnetic prepaid card, and resultingly, no payment is effected for the item.